This invention relates to improvements in buoys for mooring vessels.
In U.S. Pat. Nos. 3,823,432, and 3,908,212, there is described and shown buoys with associated mooring yokes, which are attached to the buoys in such a manner that they form a rigid integral unit therewith. In one instance the mooring yoke is rigidly attached to a bearing which surrounds the periphery of the buoy, and in the other instance the mooring yoke is attached rigidly to a turntable which rotates on the top of the buoy. The reason for this type of coupling is indicated as being required because buoys with associated mooring arrangements, of the type previously used, principally constituting a yoke pivotably hinged with respect to the turntable on top of the buoy, are subjected to tide and weather conditions which require the buoy to have a considerable inherent stability to cope with the forces exercised thereon by the mooring arrangement, without which the buoy would be tipped over. To overcome this tipping proclivity, the buoy needs to have a relatively large mass, with the result that the forces which the rigid coupling members apply to the mooring arrangement are of considerable magnitude. Also a more expensive buoy must be built than one having a lesser mass.
The advantage postulated for the arrangements described, is that, by essentially making the buoy and the yoke unitary, except for the pivoting capability, the requirement for the buoy to have a relatively large mass to provide inherent stability is considerably reduced and the buoy's tendency to tip in response to these forces is also reduced.
In U.S. Pat. No. 4,148,107 by Karl et al entitled Mooring Buoy, which is assigned to a common assignee, there is described an arrangement for coupling the mooring yoke to a buoy, which avoids the problems produced by structure built in accordance with the teachings of the indicated patents. The same benefits as are claimed for the patented structures, are obtained by providing "bumper" equipment on either side of the location of the pivotable axis of the mooring yoke to the turntable, so that, if the pivotable motion of the mooring yoke exceeds a predetermined arc, for all intents and purposes, the mooring yoke and the buoy act as if they were rigidly coupled.